Leucocytes from a total of 212 patients have been assayed against an antigen derived from pancreatic adenocarcinoma. Results, to date, have indicated that the leukocytes from 11 of 12 patients whose cancer are localized or confirmed to lymph nodes adjacent to the pancreas have identified the antigen, whereas leukocytes in 6 of 9 patients with more distant lymph node involvement have identified that antigen. Of patients with metastatic pancreatic carcinoma with either intra-abdominal spread or hematogenous spread to organs other than the liver, leukocytes from 10 of 12 patients have identified the antigen. In contrast, leukocytes from only 15 of 27 patients with metastatic pancreatic adenocarcinoma of the liver have identified these patients. There have been no false positives among the 17 patients with pancreatitis, 2 false positives among 16 patients with other diseases of the gastrointestinal tract and one false positive among 30 normal healthy controls. Among patients with carcinoma, there are 2 false positives among 71 patients with gastrointestinal tract cancer (both had cholangiocarcinoma) and 2 other false positives among 18 patients with carcinomas other than gastrointestinal origin. Preliminary studies evaluating serum "arming" of normal healthy leukocytes and the use of those "armed" leukocytes in LAI has shown concordant results in 76% of tests thus far. Further studies are underway to assess the value of "arming" and towards standardization of an antigen source.